WELLINGTON, New Zealand — A powerful magnitude-7.6 earthquake triggered large waves in the Solomon Islands on Sunday, and authorities were trying to determine whether there was any serious damage or injuries.

Government spokesman George Herming said people throughout the Pacific island chain awoke to the strong quake at 7:14 a.m. He said that people on Makira and nearby islands southeast of the capital, Honiara, reported seeing three large waves after the quake.

He said there were no immediate reports of damage or injuries.

The Pacific Tsunami Warning Center on Sunday canceled a tsunami warning after earlier issuing an alert for some Pacific islands. The center reported that sea level readings indicate a small tsunami was generated that may have caused some destruction near the epicenter.

The U.S. Geological Survey reported the epicenter was 323 kilometers (200 miles) southeast of Honiara, at a depth of 29 kilometers (18 miles).

The Solomon Islands, home to 600,000 people, was already reeling from devastating flash floods that struck Honiara and other areas April 3. The floods have killed 23 people and left 9,000 more homeless. Herming said up to 30 more people remain missing.

"It has really been a tough time," he said.

Andrew Catford, the Solomon Islands country director for World Vision, said that the aid group's staff in the Kirakira office in Makira province reported that there was no tsunami, but strong currents and heavy waves pounding the reefs. He said the group's staff evacuated to higher ground as a precaution.

"We felt this one strongly in Honiara. It was close to 30 seconds long," he said.

The Pacific Tsunami Warning Center initially issued a warning for the Solomon Islands, Vanuatu and Papua New Guinea. U.S. officials said there was no threat of a tsunami to the coasts of California, Oregon, Washington state, Hawaii or Alaska. Paul Whitmore, director of the National Tsunami Warning Center in Alaska, said powerful waves posed no threat to the U.S. West Coast or Canada after the quake.

The Solomon Islands lies on the "Ring of Fire" — an arc of earthquake and volcanic activity that stretches around the Pacific Rim.